I've got a Graflex 4X5 Series D with a f/4.5, 7 1/2" Kodak Anastigmat. I'm looking for a faster lens that would be more suitable for handheld portraits and street photography. Since the camera has a FP shutter barrel lenses are fine. I'm not to scared about cobbling up a way to mount a lens. The main thing is having enough back focal length to clear the mirror. I've got an Aero Ektar (that I bought about 40 years ago for $17!) that doesn't quite allow focusing beyond a few feet. Any suggestions?

As you have found; the Aero Ektar won't focus to infinity on the 4x5 RB Graflex. The Aeros that you see mounted on a Graflex SLR use the 3x4 body. The shortest lens I have seen that did manage infinity (just barely) on these cameras was a 180mm f/4.5 barrel Tessar. I acquired a 4x5 D from the 1930s and it was equipped with a 180mm f/3.5 Xenar, the sort of high speed lens you are talking about . That lens, because of it's size would not focus beyond 20 feet. but it does focus nicely for portraits. I had the same problem with a 180mm f/3.5 Heliar.
The Dallmeyer Pentac f/2.9 at 8" (203mm) is the right focal length but it won't really fit in the lens housing without a lot of modifications. So my final suggestion is a 210mm f/3.5 Tessar. I have one of the post war coated Jenna versions and it will mount on a standard lens board (by clipping the mounting flange) and it focuses nicely to infinity and down to about 3 feet; just about right for head shots. They are somewhat rare (I got mine from Latvia) so you might just pick up a 210mm f/4.5, Tessar or Xenar, to see if you like that focal length. Good luck.